Internal combustion engines have “standard” settings established on test bed for controlling the injection of fuel according to the operating circumstances encountered. These settings do not unfortunately take account of the conditions of ageing of the engine in real time, particularly within the actual combustion chamber (fouling of the injectors, loss of compression, deterioration of the injector nozzle opening pressures, etc.).
Admittedly, it has been proposed for engines to be equipped with knock sensors. These sensors, of the accelerometer type, therefore allow the presence of shockwaves that carry the risk of damaging the engine to be detected, and avoided, by modifying the injection parameters. However, these sensors provide only a very imperfect solution to the improvement of engines to make them less polluting and/or more efficient.
This being the case, the applicant company has set itself the task, in order to optimise the operation of the engine, of measuring the pressure within the combustion chamber.
Various devices have already been proposed for measuring this pressure. However, these are either not very reliable or too expensive because of their cost price or because of the costs that they incur (modifying the cylinder head or the engine block in order to introduce a sensor).